Towards New Milestones in Our Quest to Go Beyond the Standard Model

PREFACE

CONTENTS

Type I string theory provides a D-brane world description of our universe and leads to two new scenaria for physics beyond the Standard Model: low string scale and split supersymmetry. Lowering the string scale in the TeV region provides a theoretical framework for solving the mass hierarchy problem and unifying all interactions. The apparent weakness of gravity can then be accounted by the existence of large internal dimensions, in the submillimeter region, and transverse to a braneworld where we must be confined. I review the main properties of this scenario and its implications for observations at both particle colliders, and in non-accelerator gravity experiments. I also review the main properties of split supersymmetry and present a concrete string realization which guarantees gauge coupling unification at the conventional scale M_GUT ≃ 2 × 10¹⁶ GeV.

These two lectures are devoted to two aspects of strongly coupled quantum field theories. I first describe a proposed constraint on the structure of Btrongly coupled, asymptotically free field theories. The constraint takes the form of an inequality limiting the number of degrees of freedom in the infrared description of a theory relative to the number of underlying, ultraviolet degrees of freedom. After introducing the general idea, I discuss the application of the inequality to supersymmetric and nonsupersymmetric gauge theories, including one chiral gauge theory. In the second lecture, I discuss some of the challenges facing the idea of dynamical electroweak symmetry breaking. I review briefly constraints from precision studies and describe the idea of walking technicolor. I then discuss a model containing the ingredients for a neutrino seesaw mechanism as well as quark and lepton electric dipole moments.

No abstract received.

We give a basic review of some recent developments in local supersymmetry breaking in 4-dimensional effective theories coming from compactifications of string and M-theory in the presence of non-trivial form and geometrical fluxes.

Nucleon form factors have recently shown unexpected and spectacular features. For space-like is not constant at all, as believed for many decades, in spite of early farsighted predictions. For time-like BaBar has measured with unprecedented accuracy from the threshold up to , finding out an unexpected cross section, with plateaux and drops, in particular confirming the one just above threshold, where evidence for a ratio has also been found. The neutron time-like form factors, measured only once, and their puzzling behaviour are shortly reminded.

After a brief introduction on frame-dragging and gravitomagnetic field, including an invariant characterization of gravitomagnetism, we describe the phenomena due to spin on test gyroscopes, test particles, clocks and photons. In particular we show that when different light beams are deflected by the mass of a rotating object, with angular momentum J, and then, by gravitational lensing, observed at a far point as different images of the same source with different angular positions, there may be a significant time delay between the different images due to the spin of the deflecting body. We then discuss the time delay in the travel time of photons propagating inside a massive rotating shell. We apply this time delay, due to the spin of the shell, to the case of gravitational lensing and we show that there may be an appreciable time delay between the arrival of different images at Earth. We then consider some astrophysical configurations: a typical rotating galaxy and a typical rotating cluster, or super-cluster, of galaxies; the spin-time-delay might be large enough to be detected at Earth. This phenomenon should then be taken into account in the modeling of the time delay of different images by gravitational lensing and might be measurable in some gravitational lensing images. The spin-time-delay might give a new observable in the study of the dark matter content in rotating galaxies and clusters.

We then describe the latest results in the measurement of gravitomagnetism of Earth and Lense-Thirring effect by laser ranged satellites. Gravity Probe-B, launched by NASA on April 20 2004, will try to measure the Earth frame-dragging with accuracy of 1 % or better. A future accurate determination of the Lense-Thirring effect, at the level of 1 % accuracy, may be provided by the LARES/WEBER-SAT experiment to measure “frame-dragging” and to give other basic tests of fundamental physics and general relativity. Here we describe the 1995-2004 measurement of Lense-Thirring effect obtained by analyzing the orbits of the two laser-ranged satellites LAGEOS and LAGEOS II; this method has provided in 2004 a direct measurement of Earth's gravitomagnetism with accuracy of the order of 10 %. We first report the measurement of the Lense-Thirring effect, obtained in 2001 over nearly 8 years of data using the nodes of the LAGEOS satellites and the perigee of LAGEOS II: it fully agrees with the previous 1998 result over a period of 4 years only. Finally, we describe the 2004 determinations of Earth's frame-dragging, using the recently released Earth's gravity field models, generated by the space mission GRACE, and analyzing about 11 years of data of the nodes, only, of the LAGEOS satellites. This new analysis agrees with our previous measurements of the Lense–Thirring effect using the LAGEOS satellites and obtained with the JGM-3 and EGM96 Earth's models. However, this new determination is much more accurate and, especially, more robust than our previous measurements. Indeed, the present analysis uses the nodal rates of the two satellites only, making no use of the perigee rate, as in our previous analyses. By using the Earth model EIGEN-GRACE02S, we obtain a relative error of the order of 4 % to 8 % of the Lense-Thirring effect due to the uncertainties in the Earth static gravity field and a total root-sum-square error budget of about 5 % to 10 % due to all the error sources. Specifically, by using EIGEN-GRACE02S, we obtain: μ = 0.99 ± 0.1. This 2004 results fully confirm and improve our previous measurements of the Earth frame-dragging: the Lense-Thirring effect exists and its experimental value is within ~ 10 % of what is predicted by Einstein's theory of general relativity.

A review of the experimental status of QCD Glueballs, and the history of major investigations and developments in the research are presented. The most important missing link in experimentally establishing QCD is the lack of consensus on the experimental establishment of at least one glueball. Therefore the lecture focused on what, if any, experimental evidence can be considered compelling for the establishment of at least one Glueball. The unique experimental evidence for the I^GJ^PC = 0⁺2⁺⁺ Glue-ball, has only been successfully explained in over two decades by interaction with the 2⁺⁺ Glueball. Therefore it is resonable to conclude that the 2⁺⁺ Glueball has been experimentally established.

No abstract received.

This paper comes 40 years after the discovery of CP violation [1] in neutral kaon decay in the famous experiment of Brookhaven and after the discovery by BABAR and BELLE of the indirect (2001) and the direct (2004) CP violation [2-5] in the b sector at PEP-II and KEKB e⁺e⁻ asymmetric B Factories operating at the center of mass energy corresponding to the mass of the ϒ(4S). The Unitarity Triangle is now beginning to be constrained by the measurements at B Factories of the sides, of sin2β and now also of the angles α, and γ. We are also in presence of the very intriguing results about the measurements of sin 2β in the time dependent analysis of decay channels via penguin loops, where and .

The LHC is the last of a series of projects making use of superconductivity to investigate the composition of matter in details as fine as 10⁻¹⁹ m. Based on the performance of about 1750 large superconducting magnets it presents a numbers of technological challenges, of which the most striking is may be the construction of the 1232 15 m-long dipoles that will fill 2/3 of the 27 km long tunnel. The paper will review the main characteristics of supercolliders and of superconducting magnets for accelerators and will describe the main issue of the LHC dipoles. The construction of the accelerator is progressing well and installation has started.

This lecture is a brief introduction to RHIC physics and some of the striking phenomena that have been observed there. Attempts are made, where possible, to draw attention to similar behavior in heavy ion and elementary systems.

A high luminosity (10³⁴–10³⁵ cm²/s) linear electron-positron Collider (CLIC) with a nominal centre-of-mass energy of 3 TeV is under study in the framework of an international collaboration of laboratories and institutes, with the aim to provide the HEP community with a new facility for the post-LHC era.

After a brief introduction of the physics motivation, the CLIC scheme to extend Linear Colliders into the Multi-TeV colliding beam energy range will be described. In the following, the main challenges and the very promising achievements already obtained will be presented.

Some recent results in the study of four dimensional supergravity flux compactifications are reviewed, discussing in particular the role of torsion on the compactification manifold in generating gauge charges for the effective four dimensional theories.

We address the phase structure of color superconducting quark matter at high quark density. Under the electric and color neutrality conditions there appear various phases as a result of the Fermi surface mismatch among different quark flavors induced by finite strange quark mass; the color-flavor locked (CFL) phase where quarks are all energy gapped, the u-quark superconducting (uSC) phase where u-quarks are paired with either d- or s-quarks, the d-quark superconducting (dSC) phase that is the d-quark analogue of the uSC phase, the two-flavor superconducting (2SC) phase where u- and d-quarks are paired, and the unpaired quark matter (UQM) that is normal quark matter without pairing. Besides these possibilities, when the Fermi surface mismatch is large enough to surpass the gap energy, the gapless superconducting phases are expected. We focus our discussion on the chromomagnetic instability problem related to the gapless CFL (gCFL) onset and explore the instability regions on the phase diagram as a function of the temperature and the quark chemical potential. We sketch how to reach stable physical states inside the instability regions.

We briefly review the spin-bit formalism, describing the non-planar dynamics of the , d = 4 Super Yang-Mills SU(N) gauge theory. After considering its foundations, we apply such a formalism to the su(2) sector of purely scalar operators. In particular, we report an algorithmic formulation of a deplanarizing procedure for local operators in the planar gauge theory, used to obtain planarly-consistent, testable conjectures for the higher-loop su(2) spin-bit Hamiltonians. Finally, we outlook some possible developments and applications.

I present an interesting mechanism to predict a maximal atmospheric angle, which is based on a maximal CP violating phase difference between second and third lepton families in the flavour symmetry basis. In this framework, a discussion of the general formulas for θ₁₂, |U_e3|, δ and their possible correlations in some limiting cases is also provided.

The NMSSM contains a Higgs singlet in addition to the two Higgs doublets typical of the MSSM, thus resulting in a total of seven physical Higgs mass states. The phenomenology of the NMSSM Higgs sector varies considerably from that of the MSSM and there are good prospects of finding in regions of the NMSSM parameter space Higgs signals that cannot be reproduced in the MSSM. We examined the two-photon decay mode of a Higgs boson and found that up to three Higgs bosons could be observable over sizable regions of NMSSM parameter space, through the conventional detection channels used at the LHC.

We give a theoretical interpretation of experimental data on hadronic multiplicity, as a function of centrality and rapidity, in Au – Au and d – Au collisions at RHIC, in the framework of the Parton Saturation Model.

We define and use two dispersive techniques, based on data, analyticity and dispersion relations to handle the nucleon form factors.

In the first case, we use the available information on the ratio between the electric and magnetic proton form factors, coming from recent space-like and time-like data and theory, as inputs in a dispersive approach that gives as outcome a complex description of this ratio, valid in the whole q² plane.

In the second case, by inverting a dispersion relation for the magnetic nucleon form factors and by considering the data and the pQCD asymptotic behaviour, we reconstruct these form factors in the unphysical region. We found resonances and phases in agreement with the expectations.

A distributed classification paradigm known as collaborative tagging has been successfully deployed in large-scale web applications designed to manage and share diverse online resources. Users of these applications organize resources by associating with them freely chosen text labels, or tags. Here we regard tags as basic dynamical entities and study the semiotic dynamics underlying collaborative tagging. We collect data from a popular system and focus on tags associated with a given resource. We find that the frequencies of tags obey to a generalized Zipf's law and show that a Yule-Simon process with memory can be used to explain the observed frequency distributions in terms of a simple model of user behavior.

In situations where the signal of the analysed particle is tangled up with orders of magnitude more background, its analysis may benefit from the use of a pattern classification method to discriminate the signal out of the background candidates. We present and explain the basic Linear Discriminant Analysis and the modifications brought – the use of cascaded cuts and of a locally optimized criterion – to adapt it to the conditions encountered in the field of heavy ion Physics. We show that this optimized multicut Linear Discriminant Analysis has a higher performance than classical selection cuts and provides a very fast and easy selection cut optimization.

The recent developments in superstring theory prompted the study of non-commutative structures in superspace. Considering bosonic and fermionic strings in a constant antisymmetric background yields a non-vanishing commutator between the bosonic coordinates of the spacetime. Likewise, the presence of constant Ramond-Ramond (RR) background leads to a non-vanishing anti-commutator for the Graasmann coordinates of the superspace. The non-vanishing commutation relation between bosonic coordinates can also be derived using a particle moving in a magnetic background, we use superparticle to show how the non-commutative structures emerge in superspace. The derivation is original and it is shown that only a D0-brane in supergravity background reproduces the results obtained in string theory.

The Run I results on the searches for new physics in photon final states were intriguing. The rare . candidate event and the measured event rate for the signature , which was 2.7 sigma above the Standard Model predictions, sparked signature-based Bearches in the γγ + X and ℓγ + X channels. With more data in Run n we should be able to answer a simple question: was it an anomaly or were the Run I results the first evidence for new physics? We present searches for New Physics in Photon Final States at GDF Run II, Fermilab, with substantially more data and a higher collision energy, 1.96 TeV, and the upgraded CDF-II detector.

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